KRY12_02 Bunmahon

Between the 13th and 18th June 2012, the RV Keary carried out seabed mapping off the coast of Bunmahon, Co. Waterford. This survey was conducted in support of the INTERREG funded Atlanterra Project, which has designated the Bunmahon area as a Geo-park. Learn more about Atlanterra at http://www.gsi.ie/Programmes/Heritage+and+Planning/Heritage/Atlanterra.htm.

During the survey work the Keary was based in the port of Dunmore East, from which the vessel could transit to the survey area. Existing bathymetric data lay to the south, having been collected by the RV Celtic Voyager in 2007, and it was ensured that the RV Keary's coverage overlapped with that to provide quality control on the data.

Two uncharted shoals were mapped during the course of the survey, with this information then delivered to the UK Hydrographic Office (UKHO) in the form of H-notes. The UKHO will then issue a Notice to Mariners, alerting them to these hazards and will include the shoals in New Editions of charts.

Examples of the data collected are below:

Seabed data collected off Bunmahon shown as shaded relief

Backscatter image of the seabed off Bunmahon. The RV Keary uses a multibeam sonar to map the seabed - when the sound waves it produces reflect back off the seabed, the strength of the return provides information on the hardness of the seafloor material. This greyscale map was produced using that data. Note also that this image shows the data collected by the Celtic Voyager to the south.

Shoal discovered during survey operations - originally charted at 14m depth (LAT) but now found to be at 7.5m depth (LAT). The top half of the image shows it in plan view, while the lower half is a profile view. LAT = Lowest Astronomical Tide.